Yeah,I would use better test kits,,The main thing is look at the overall health of what you are keeping in the tank,If the organisms are doing fine than you are on the right path,,Take pictures of the corals and coraline algae in the tank,at a set time as in every month,that way you can see the changes in their growth...Since you see the tank everyday you won`t see a big difference until the organism is a lot bigger than you remember....One Weird thing that I have noticed is that the coraline algae is the first thing that starts to go south when a tank starts having problems,It can also tell you,when your lighting level or intensity is changing,,because Different coraline algae likes different levels or intensity of light....What I like to do is put different varieties of coraline algae in a tank,So in one system one algae will grow fast as the lighting changes the algae growth or type shifts...It helps cut down on the growth of undesirable algae,So it is harder for it to get a foothold on the tank..Microalgae doesn`t grow on something that is living,what it does is it attaches to an area that is dead and smoothers by its growth things that are living,When the coraline dies or is not covering the rocks,algae can grow.......